Bike Check: Isak Leivsson's Handmade 130mm Jib Bike

Feb 4, 2022 at 12:41
by Alicia Leggett  


If you haven't noticed Isak Leivsson's handmade downhill bikes out on the World Cup tracks, surely you remember his legendary backflip attempt in his race run at Snowshoe, right? Now, he's made a bike that will flip and spin a little better than his several homemade downhill race bikes, which have roughly 500mm chainstays (give or take a centimeter, depending on the version).

Isak Leivsson, a former bike tester for Pole Bicycles, has experimented with building his own bikes for nearly two years now. What started as a way to make himself some custom tools has morphed into about 10 complete bike builds and several other bits and pieces.

After building only full suspension bikes that have been focused on racing, Isak decided he wanted to focus a bit more on fun by building something that would work well for tricks and low-speed riding. 130mm of rear travel, he said, felt like the right compromise between capability and fun: it's poppy enough but can handle some "big-ish" hits. He chose 27.5" wheels because smaller-wheeled bikes spin much more easily than 29ers.

The bike borrows much of its geometry from the downhill bikes he's built, but scaled smaller and with slightly steeper angles.

Geometry
Reach: 430mm
Chainstays / rear center: 455mm
Wheelbase: 1216mm
Front center / rear center: 1.67
BB height: 350mm
Head angle: 64.5 degrees
Stack: 574mm
Seat tube height: 410mm
Wheel size: 27.5"
Fork travel: 140mm
Rear travel: 130mm

bigquotesI referred to it as a jib-bike, by which I guess I mean pretty much anything that seems fun to do unrelated to speed.Isak Leivsson

Isak designs for function and the form follows.

The most important part of the design process is figuring out what ride characteristics he wants in the bike and translating that into geometry and kinematics, he said. He then uses Linkage x3, a suspension kinematics software tool, to plug in the dimensions of the bike's side profile and suspension points, tweaking the numbers until he has what he wants. To make reading off the numbers easier, he exports the side profile to CAD software before beginning the build. Later, once the main frame parts are built and in-hand, he goes back to the design stage to create the plate cutouts for the brake mount, pivot points, and shock mount pieces, along with the rocker links.

With the frame profile designed, he makes jigs for the front triangle, seat stay, chainstay, and shock mount, then usually machines the pivot points before welding the front triangle together. After that, it's essentially a matter of notching and welding, he said. He mills the pivot and bearing holes for the rocker out of flat plate, cuts the outer design with a band saw, and finishes the cuts with an angle grinder.

With the number of small spacers and other bits and bobs to make before assembling, Isak said, he's usually eager to ride the bike by the time he's done building and finishes it with just a quick coat of spray paint, if anything.

The front triangle of this particular build was intended for a hardtail and hung on Isak's wall for a while before he decided to turn it into this jib bike. He had a few challenges, like problem-solving how to make the rocker pivot point without making new jigs for this one-off, out-of-order project, but he seems to have sorted it out.

The head tube, bottom bracket, seat-tube insert, hose guides, and direct mount brake mount are from Bikefabsupply, and dropouts and hanger are from Paragon Machine. He made all the suspension mount parts and plate cutouts himself.

Isak said the geometry is similar to that of his downhill bikes, but scaled smaller and with slightly steeper angles for maneuverability. Although this bike is much shorter than the race bikes he's built, he kept the same ratio of front center to rear center, as he likes to be in roughly the same position on all his bikes. "My location within the bike is close to the same, as the wheels are relatively speaking at the same place compared to the largest part of my force input to the bike, my feet," he explained. "I am just balanced by a narrower triangle."

Isak designs his bikes for functionality, focusing on geometry, suspension kinematics, strength, stiffness, and simplicity of use and manufacture, he said. His emphasis on building a bike around specifically what he wants shows in the bars he built for this bike: It's nearly impossible to find bars as tall as what he wants, so he built them himself. It's fun, he learns something, and he gets exactly what he wants. He said these current 115mm rise bars are a bit taller than he'd ultimately like, so he plans to swap out to a 90mm set in the future.

While some might say his 455mm chainstays are too long for a bike of this nature, he said, he likes them that way because their length allows him to finesse and control his input for manuals, bunny hops, and jumps much more easily than on a bike a shorter rear end. He wants to stand upright, and the long chainstays and tall bars allow him to do so. "This setup works out great for me, I can ride the bike in the position I like without having to worry about looping out when I pull back," he said."

Isak says he often receives questions about the tubing he uses, so here are a few answers. This bike is made completely of 0.035" wall tube thickness, but of varying outside diameters. The downtube and seat tube are 1 3/8" (35mm), the top tube is 1 1/4" (31.8mm), chainstays are 1", and the seat stays are 3/4".

In the near future, we'll likely see this bike's bigger sibling from Isak. He says he recently finished a downhill bike that's meant for tricks and jumps - essentially a smaller version of his V5 downhill race bike.

To learn more, find Isak's welding and riding on Instagram at @isakleivsson. If you don't see any updates, it probably means he's out having too much fun on the jib bike.

Isak said he's most proud of the handlebars on this bike. Everything else is similar to on his downhill bikes, but the bars - albeit a bit crude and built somewhat by eye - are all new and are a success.



137 Comments

  • 257 2
 The bars...looks like it has a bmx background.
  • 15 5
 I hope there 28.99mm in diameter
  • 4 6
 Haha! Great comment
  • 25 0
 "...as a Professional Engineer and CrossFitt-er I can confirm the this bike does indeed, have a BMX background, just like me."
  • 17 2
 455mm chain stays are pretty darn long for a "jib" bike
  • 10 10
 Looks like a session
  • 9 0
 bob scerbo would be happy
  • 5 0
 Old school Fred'z vibes
  • 3 0
 @gally-nh: brings back memories
  • 8 0
 My kneecaps need stitches just looking at those bars.
  • 3 0
 came for the bmx influence
  • 3 0
 Looks like Norco wiped any evidence of its existence off the internet, but they made for one year only during the early days of Whistler Crankworx a bike called the Boneyard which featured a steel frame with a short travel coil shock, pegs front and back, a gyro, marzocchi dirt jumper fork, single speed hub, 24" wheels and one of those steel bmx style bars that always rusted on any of their other dirt jumpers of the year.
  • 2 0
 @ohklee: oh I remember the “Norco 420” was a steel version of the aluminum “4by” but never made it to the masses.

m.pinkbike.com/photo/118183
  • 1 0
 @dh-bomber: Yesss! that's the one. Imagine giving that to all the slopestyle kids now and see what they can do.
  • 1 0
 @ohklee: haha they would be tripped out looking at it. I bet all the BMX guys would love it, like Brad Simms
  • 2 0
 @pinegrove: he makes a good point though, I have a 130mm bike with 425 chainstays and the loop out problem is real. Probably not so bad on bikes with longer reach, but my bike is very similar to this one. 430 reach, 150/130 travel 27.5. Fun bike but muh gawd is it sketchy on fast, steep trails.
  • 2 0
 @ripridesbikes: Loop out problem ? what are you looping out on ? Sounds like you are more concerned about your bikes handling on trails and not on jumps and jibby stuff. Having sub 435mm chain stays make 360's and half cabs so much easier and the bike more responsive and playfull. Just don't lean so far back if ya loopin out
  • 2 0
 @pinegrove: Yeah, to be fair, I do criticize my bike for it's trail manners quite a bit. I would say though, the 430 reach and the 425 stays make big bunny hops and manuals feel unstable I wouldn't want stays anywhere near as long as this guys but I think just a hair longer would help.... could definitely be related to the bike being a little too small for me too. It's great for jibs and dirt jumps though. It almost fits like a big dirt jumper.
*Also, I desperately want to learn half-cabs.
  • 1 0
 @ripridesbikes: I ride a large with a longer reach so I can't really talk since I have more room to work with in the front. Bikes are weird and having a trail bike ride trails is usually more important than actually tricks, especially if you have a dirt jumper you can ride on the side. try some half cabs on a smaller bike if you have one around and just push off a wall for momentum.
  • 1 0
 @SacAssassin: Fat Tony and 'The Boys' removed my kneecaps long ago
  • 1 0
 @SacAssassin: no need for stitches if you have BMX background!
  • 27 0
 I don't think I'd get along with chainstays that long, but 27.5 jib bikes are too few and far between these days. such a cool project
  • 4 0
 The dude is pretty tall, right?
  • 5 1
 @hamncheez: but then only 430 reach. i am only 6´1" and feel really cramped on anything under 460 reach
  • 3 0
 @funkzander: 115mm riser bars
  • 2 2
 But they're 2" shorter than his DH

@hamncheez: 187cm

@funkzander: stand and deliver
  • 2 1
 Chainstays that long really aren't the devil as these comment sections might lead you to believe. For a 6' person I think the sweet spot is 445 on a 27.5 wheel and 440 on a 29er. I switch between 2 bikes, one that's 442 27.5 and one that's 458 27.5 and don't notice a difference except at high speeds.
  • 1 0
 @hamncheez: According to the PB profile of his Pole bike, he's 6'2", which is tall, but not extremely so.
  • 2 0
 @funkzander: I'm 5'10 and 430 feels cramped.
  • 28 2
 I bet that thing handles like it's on rails.
  • 4 0
 Underrated pun
  • 1 2
 Shit! hit the wrong button!!!! Meant to upvote because I agree, and I have terrible body control.... hence the many crashes i have put myself in...
  • 1 0
 @bikeryder85: He definitely kept it on track.
  • 21 2
 This is so much cooler than the bikes we're all building...
  • 12 1
 Speak for yourself Wink
  • 3 0
 @Tambo: what you got planned tam? Come on don't tease!
  • 3 0
 @dirtyburger: bikes. Really, I can't tell you Smile
  • 1 0
 @Tambo: 190*50 imperial
  • 1 0
 @Tambo: cool is subjective, but I think we can assume the quality of yours might be slightly better at least.
  • 1 0
 @pimpin-gimp: fingers crossed!
  • 12 0
 This is sweet!
  • 1 0
 The inspired bars are not the same measurements as the rest of the industry. The inspired bikes bars are measured to the end of the grip while most bars are measured to the top of the bend.
  • 1 0
 @headmechanix: maybe it's a trials bike thing. The few I saw on the site were measured that way.

Either way, still pretty tall.
  • 10 0
 @mdinger: it's a Tartybikes thing. Measuring to just the top of the bend doesn't give a true indication of how high the bars are where you actually hold on. Lots of trials bars have a very high upsweep but smaller bend...with the usual measuring system they'd seem very low on paper when in fact because of the upsweep the end of the bar is actually quite a lot higher. By measuring to the end of the bar you get a more meaningful indication of how tall a bar actually is
  • 2 0
 @mdinger: It's a BMX thing too. It's always made more sense to me than shoulder-to-shoulder measurements. The other option is for bar manufacturers to provide both. They have the info, they just need to put it out there.
  • 1 0
 Yes trials bars work if you like narrow bars?
but have found wider options !
Way cheaper too!
www.ebay.co.uk/itm/154572065208?hash=item23fd3689b8:gMad -EAAOSwchphGoyv
  • 1 0
 @aliclarkson: Yes trials bars work if you like narrow bars?
but have found wider options !
Way cheaper too!
www.ebay.co.uk/itm/154572065208?hash=item23fd3689b8:gMad -EAAOSwchphGoyv
  • 1 0
 @aliclarkson: How about trying these, will work better than moving your grips out?
But could do with a durability test?
  • 3 0
 @aljoburr: I'm perfectly happy with my Inspired bars thanks Razz
  • 1 0
 @aljoburr: yes, go test those £20 risers. I know a lawyer in Shenzen. Based on his prior choices, bars are at least 800mm wide. Are those 203mm Storm HCs? This is starting to look like finished product
  • 1 0
 @aliclarkson: thanks for clarifying. I like tartybikes. They're nice to work with.

@aljoburr: the article specifically said you can't find 115 mm high rise bars. I found some. It didn't state they needed to be 800 mm width though so I wasn't sure if they suited the intended purpose.
  • 1 0
 Stooge Cycles have some 100mm rise bars at 820mm width (and all of the back sweep).

Although the clamp is 22.2mm so you have to run a (supplied) 31.8mm shim
  • 1 0
 @Sambikes11: Any idea if there are any US companies producing bars like Stooge? Love the style, I just don't want to have to ship them across the pond.
  • 3 0
 @Sumnerrenegar: honest answer: the nearest moto parts dealer

Some push bike specific options are Surly and Velo Orange but they're probably not very highly rated on the astm scale. Oddity and Doom Bars are the fancy made in usa stuff.
  • 1 0
 @Sumnerrenegar:

I think Whisky Millhouse bars are USA, they’re carbon I think but look super nice.

Stooge are very much a one man band and he seems to ship stuff all around the world
  • 1 0
 @Sumnerrenegar: Stout Bikes would do something like that. Super well made and affordable. I have 4 inche rise on my NS Capital. @mattty
  • 3 1
 Really really cool experimentation by top riders at the mo with this and Neko's bikes.

I wonder how much they play with the stiffness of these bikes? Intuitively it looks like this would be flexier than most bikes with the steel tubes and less reinforced linkage parts eg two piece rocker instead of a machined one.

Not a criticism, I'm interested as no doubt Isaac and neko are much more attuned to frame stiffness than I am
  • 4 0
 “Stiffness” is a marketing gimmick.
  • 2 0
 @stubs179: Bronson.3 upper shock hardware: 20x8mm. 5010.4 upper shock hardware: 25x8mm. Bronson.4: 30x8mm. Stiffness is precision. Stiffness is what you want, optimized for comfort, weight, and durability
  • 2 0
 According to Young’s Modulus: for the same thickness, steel is 3x stiffer than aluminum
  • 1 0
 @ceecee: that’s what she said. But really, no mtb frame is stiff. It’s all just marketing and people talking. We need “stiff” carbon wheels, but not too stiff and then we will run out 2.6 tires at 18 psi. Lol
  • 2 0
 @stubs179: deflection is immeasurable and without scientific merit. Teach your children
  • 2 0
 What Isak and Neko are doing are entirely different.

Let none of you think I am disrespecting Neko with his program, but, he's picking geometry he likes, and getting a genius such as Frank The Welder to make his bikes. And then, he's testing them. I'd be surprised, if it all works out for Neko, if he didn't market his and FTWs frames. He's done his sums for his racing efforts, has enough sponsorship and I guess money, through that sponsorship, to cover his racing, and, he's going to get far more coverage for he and his sponsors with his efforts with 'his' frames. It is Brilliant self marketing, for one of the 'Good Guys' in racing. I wish him all sorts of success.

Isak : well , I like his line of "I ride Bikes and Weld a Lot" in his Instagram. Have to say, it's the first time I've ever ventured into the 'IG' thing. I'm old, and, not that interested in such things.

And, with seeing his various bikes put up, over time, his "I Weld a Lot", is not a lie.

His welding has improved Immensely. And his fabrication skills.

I love seeing peoples 'journey' through their chosen path. I'm a TIG Welder and Frame builder of over 45 years experience, I know what I'm writing about. I like that he has a picture of at least one of his design mistakes, with a folded seat stay / 'push' tube to an underslung rocker bike he did, with tiny tubing, and, from the info he put up about tubing preferences, thin walls. A learning experience for him.

He seems committed to relatively small tubing, with thin walls. Me, I use much more of a variety of tube sizes and wall thicknesses. A 34.9 /35mm Steel x .9mm wall thickness (std. 4130 Normalized condition ? - or some Cycle Tube makers proprietary material?) as a downtube, is not something I think can last for long, but, maybe he has some exotic tubing to be confident enough to use something that small and thin? I use 44.45mm x 1.2mm downtubes on my DH and Enduro frames. And, my 'chainstays (on my steel swingarms), are stacked 12.7mm square tubes, in either 'stacks' of two or three, in a variety of wall thicknesses. It appears, he may have settled on this Swingarm - as in, a single pivot arm, directly going to the axle - then a 'push' tube to his rocker arms. Me, I like a Swingarm such as that, and, I've run long chainstays for years now like he has done with most of the frames I've seen from him.

I hope to see much more of both Isak's and Neko's' - well, especially Isak, as He is Making / Building Things - progression with their projects. I'm impressed by both of their efforts. Bravo to Both of them.

There is Nothing better than Making Your Own 'Things'.
  • 4 0
 YO! the bars are sweet first time i have seen handmade 31.8 bars. mitering on 22.2 is smart.
  • 5 0
 I would love to see him do a 4" travel, 27.5/26 mullet slalom bike
  • 21 3
 Bring on the jibcountry bikes!
  • 4 0
 Man I'd be so nervous that open tube on the handlebar would cleave a chunk out of me! This thing is sweet though
  • 4 0
 Love these. Jib bikes are the best!!
  • 4 0
 So good. More jib content plz!
  • 4 0
 MAD DOG.
  • 4 0
 This is so cool
  • 2 0
 when mad max finally runs out of fuel on his ford falcon he rides this beast
  • 3 0
 What's the weight on something like that?
  • 2 1
 In you have to ask that question it´s not for you
  • 2 0
 was thinking the same..
the bike can look mint AF, but if you can't lift it off the ground there might be a little problem while jibbing Big Grin
  • 1 2
 @bohne: average BMX is heavier than 99% of Yeti SB150 in XL so…
  • 1 0
 I’ve seen him backflip an e-bike several times. I’m guessing this one is lighter than an e-bike.
  • 1 0
 @calmWAKI: ehhh what? maybe 25 years ago
  • 2 0
 That thing is so sick !!! Those bars look like haro knee savers. For those who know what those are .
  • 2 0
 And Jib is finally a category! Super looking bike, full points for putting in the work to have what you want.
  • 3 0
 Sweet rig!
  • 2 0
 that looks like so much fun!
  • 2 0
 love it, those bars are great!
  • 2 0
 Long Stays but tall BB. Looks super rad!!!
  • 2 1
 RAD! but atent these called 'play bikes' ? Would be even rafter in 26. And, I would kill for those pedals
  • 1 0
 Stoopid fone
  • 1 0
 I would love some of those bars, they sure tug at the old bmxer heartstrings. Such a classic shape.
  • 1 0
 Rad bike You should set up a company and sell them..I for one would buy that
  • 1 0
 I love my Bird Aether 7 jib bike! Maybe I should throw on some high rise bars now
  • 1 0
 50mm Title risers on mine. Slammed 35mm stem though so not really out of the ordinary height but looks so clean Smile
  • 1 0
 Th DH play bike is now on his Instagram and it is definitely worth checking out too. Custom bikes are cool
  • 2 0
 Is this what the Ghost riot tried (and failed?) to be?
  • 1 0
 laughed way too hard on that one Big Grin
  • 1 0
 Congratulations for your work and the result, it look likes good. I'd like to have your skills as a welder.
  • 1 0
 For all the people talking about how awesome Jib bikes are, mine is for sale on the buy/sell page. Just sayin.
  • 2 1
 We need a video on this build!
  • 3 2
 Plenty of room for a water bottle
  • 1 0
 "...and the Steampunk Bike of the Year Award goes to...."
  • 1 0
 Isak is the coolest. The stuff he does is so rad.
  • 1 0
 "Low speed" being a relative term...
  • 1 0
 80s bike porn is alive and thriving.
  • 1 0
 One of the coolest bikes I've seen in a long while! Well done Isak!
  • 1 0
 he should try 26" wheels back to front
  • 1 0
 major respect for his TIG beads!
  • 1 0
 How did he get the bike to balance between the railroad tracks?
  • 1 0
 that much rise would feel like shit
  • 1 0
 If they don't find you handsome, they should at least find you handy!
  • 1 0
 rad
  • 1 0
 Han er drit gal
  • 1 0
 That is vulgar
  • 1 0
 But in a nice way?
  • 1 0
 YES BARS YES!
  • 1 0
 Needs smaller wheels
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